Efficient fluorescence strategy based on a DNA tetrahedral nanodevice for intracellular hypochlorous acid imaging.

Hypochlorous acid (HClO) is a pivotal effector molecule in the immune defense system of living organisms and plays a critical role in maintaining physiological homeostasis. Aberrant HClO levels are reported to be associated with numerous diseases, making it a promising disease biomarker in clinical settings. In this study, an efficient fluorescence detection strategy based on a DNA tetrahedron was constructed, for specific HClO imaging in living cells. This method enables specific recognition of HClO through a phosphorothioate (PS) modification site. Under optimized conditions, this method showed a detection range of 0.05-5 µM, with a limit of detection of 31.5 nM, enabling highly sensitive and specific detection of HClO. Recovery tests futher confirm its stable and accurate detection performance in complex samples. Moreover, this method was successfully applied to HClO imaging in RAW 264.7 cells, demonstrating satisfactory results. Overall, the method proposed here has many advantages, including high sensitivity, excellent stability, strong resistance to interference, simple detection process, and fast response, offering it considerable potential for biochemical analysis and disease diagnosis.